JP2017195497A - Imaging element mounting substrate, imaging device, and imaging module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging element mounting substrate, an imaging device, and an imaging module that can maintain airtightness of the imaging device and suppress cracks in or breakage of a wiring board.SOLUTION: An imaging element mounting substrate 1 comprises: an inorganic substrate 4 including a central area 4b that has an imaging element 10 mounted on its top face and a peripheral area 4a that is provided to surround the central area 4b; a frame-like wiring board 2 that is provided on the top face of the inorganic substrate 4 and surrounds the central area 4b; and a joint material 15 that is provided between the inorganic substrate 4 and wiring board 2. A portion located in the peripheral area 4a of the inorganic substrate 4 is inclined upward, and the joint material 15 is provided inside an outer edge of the inorganic substrate 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging element mounting substrate, an imaging apparatus, and an imaging module on which an electronic element, for example, an imaging element such as a CCD (Charge Coupled Device) type or a CMOS (Complementary Metal Oxide Semiconductor) type is mounted.

  2. Description of the Related Art Conventionally, there has been known an image sensor mounting substrate including an inorganic substrate and a wiring substrate bonded to the inorganic substrate through a bonding material. An imaging device in which an electronic element is mounted on the imaging element mounting substrate is known (see Patent Document 1).

JP 2010-220245 A

  In the technique disclosed in Patent Document 1, an imaging element mounting substrate is miniaturized in response to a recent demand for miniaturization of an imaging apparatus. In response to this demand for downsizing, wiring boards or inorganic boards made of insulating layers and the like are also downsized.

  However, due to the miniaturization of the wiring substrate or the inorganic substrate, the bonding area for bonding the wiring substrate and the inorganic substrate is reduced, and when the bonding material provided between the wiring substrate and the inorganic substrate is pressed, inorganic In some cases, it flowed out to the side of the substrate. When the bonding material flows out to the side surface of the inorganic substrate, when the lens holder is bonded to the image pickup apparatus, the airtightness may be lowered or the lens holder may be poorly bonded.

  Further, there is a case where stress is applied to the wiring board through the inorganic substrate due to stress from the outside of the imaging device, and the wiring board is cracked.

  An object of the present invention is to provide an image pickup device mounting substrate, an image pickup device, and an image pickup module capable of maintaining the airtightness of the image pickup device and suppressing cracks or cracks in the wiring board.

  An image sensor mounting substrate according to one aspect of the present invention includes an inorganic substrate having a central region on which an image sensor is mounted and a peripheral region provided so as to surround the central region, and an upper surface of the inorganic substrate. A frame-shaped wiring board that surrounds the central area, and a bonding material provided between the inorganic board and the wiring board, and a location located in the peripheral area of the inorganic board is The bonding material is provided inside the outer edge of the inorganic substrate.

An imaging device according to an aspect of the present invention includes an electronic element mounted on the electronic element mounting portion of the inorganic substrate of the imaging element mounting substrate.

An imaging module according to one aspect of the present invention includes a lens holder provided on an outer surface of the wiring board of the imaging element mounting substrate.

  An image sensor mounting substrate according to one aspect of the present invention includes an inorganic substrate having a central region on which an image sensor is mounted and a peripheral region provided so as to surround the central region, and an upper surface of the inorganic substrate. A frame-shaped wiring board that surrounds the central area, and a bonding material provided between the inorganic board and the wiring board, and a location located in the peripheral area of the inorganic board is The bonding material is provided inside the outer edge of the inorganic substrate. Thereby, even if the bonding material is pressed, it is possible to reduce the exposure of the bonding material to the side surface of the inorganic substrate due to the peripheral region inclined upward. Therefore, it is possible to reduce the exposure of the bonding material for bonding the wiring substrate and the inorganic substrate to the outside, and it is possible to reduce the airtightness of the imaging device or the poor bonding of the lens holder.

  In addition, since the peripheral portion of the inorganic substrate is inclined to the upper surface side, the inclined portion becomes a spring, and the stress applied from the outside of the imaging device can be relieved. Therefore, it is possible to reduce the possibility of cracks or cracks occurring on the wiring board.

(A) is a top view which shows the external appearance of the image pick-up element mounting board | substrate and imaging device which concern on the 1st Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). is there. (A) is a top view which shows the external appearance of the electronic module which concerns on the other aspect of the 1st Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). (A) is a top view which shows the external appearance of the image pick-up element mounting board | substrate and imaging device which concern on the 2nd Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). is there. (A) is a top view which shows the external appearance of the electronic module which concerns on the other aspect of the 2nd Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). (A) is a top view which shows the external appearance of the image pick-up element mounting board | substrate and imaging device which concern on the 3rd Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). is there. (A) is a top view which shows the external appearance of the image pick-up element mounting board | substrate and imaging device which concern on the 4th Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). is there. (A) is a top view which shows the external appearance of the image pick-up element mounting board | substrate and imaging device which concern on the 5th Embodiment of this invention, (b) is a longitudinal cross-sectional view corresponding to the AA line of (a). is there.

<Configuration of Imaging Element Mounting Board and Imaging Device>
Hereinafter, some exemplary embodiments of the present invention will be described with reference to the drawings. In the following description, an image pickup apparatus has a configuration in which an electronic element is mounted on an image pickup device mounting substrate and a lid is bonded to the upper surface of the image pickup device mounting substrate. A configuration having a lens holder provided on the outer surface side of the imaging element mounting substrate is an imaging module. Any direction of the imaging element mounting substrate, the imaging apparatus, and the imaging module may be upward or downward. For convenience, the orthogonal coordinate system xyz is defined and the positive side in the z direction is upward.

(First embodiment)
With reference to FIG. 1, the imaging device 21 and the imaging element mounting substrate 1 according to the first embodiment of the present invention will be described. The imaging device 21 in this embodiment includes an imaging element mounting substrate 1 and an imaging element 10.

The image pickup device mounting substrate 1 is provided on the upper surface of the inorganic substrate 4 and the inorganic substrate 4 having a central region 4b on which the image pickup device 10 is mounted and a peripheral region 4a provided so as to surround the central region 4b. The frame-shaped wiring board 2 surrounding the central area 4b and the bonding material 15 provided between the inorganic board 4 and the wiring board 2 are provided, and the portion located in the peripheral area 4a of the inorganic board 4 faces upward. The bonding material 15 is provided inside the outer edge of the inorganic substrate 4.

  The image pickup device mounting substrate 1 includes an inorganic substrate 4 having a central region 4b on which an image pickup device 10 is mounted and a peripheral region 4a provided so as to surround the central region 4b.

  As the material constituting the inorganic substrate 4, for example, a material having a high thermal conductivity is used. By using a material having a high thermal conductivity, heat generated when the imaging element is used or heat generated when the wiring substrate 2 and the inorganic substrate 4 are bonded by the bonding material 15 can be easily released to the outside. be able to. Examples of the material for forming the inorganic substrate 4 include an aluminum nitride sintered body, a silicon nitride sintered body, or silicon (Si). In addition, when the material for forming the inorganic substrate 4 is, for example, an aluminum nitride crystal or a silicon nitride chamber crystal, the inorganic substrate 4 may be a laminate including a plurality of insulating layers. In addition, the inorganic substrate 4 may have a conductive layer deposited on the surface of a laminate composed of a plurality of insulating layers. In addition, the image sensor 10 is mounted on the central region 4 b located on the upper surface of the inorganic substrate 4.

Moreover, a metal material is also used as the material of the inorganic substrate 4, and examples of the metal material include stainless steel (SUS), Fe—Ni—Co alloy, 42 alloy, copper (Cu), and copper alloy. For example, when the wiring board 2 is an aluminum oxide sintered body having a thermal expansion coefficient of about 5 × 10 ⁻⁶ / ° C. to 10 × 10 ⁻⁶ / ° C., the inorganic substrate 4 is about 10 to 17 × 10 ^−6. Stainless steel (such as SUS410 or SUS304) having a thermal expansion coefficient of / ° C. can be used. In this case, the difference in thermal contraction and thermal expansion between the wiring substrate 2 and the inorganic substrate 4 is reduced, so that deformation of the central region 4b can be reduced. As a result, the optical axis shift between the image sensor 10 and the lens provided in the lens holder can be suppressed, and the sharpness of the image can be maintained satisfactorily. Further, when the inorganic substrate 4 is made of a metal material, it is possible to reduce the magnetization of the inorganic substrate 4 due to the nonmagnetic material. Therefore, it is possible to reduce the interference of the inorganic substrate 4 with the function of the external device such as lens driving.

  For example, a CCD (Charge Coupled Device) type or a CMOS (Complementary Metal Oxide Semiconductor) type imaging element is used as the imaging element 10. In addition, the image pick-up element 10 may be arrange | positioned on the upper surface of the inorganic board | substrate 4 through the adhesive material. For example, silver epoxy or thermosetting resin is used as the adhesive.

  The imaging element mounting substrate 1 includes a frame-like wiring substrate 2 that is provided on the upper surface of the inorganic substrate 4 and surrounds the central region 4b. The wiring board 2 is made of an insulating layer, and the wiring board 2 is provided with an image sensor connecting pad 3 on the upper surface. Although not shown, a plurality of external circuit connection electrodes connected to the external circuit or the inorganic substrate 4 may be provided on the lower surface of the wiring board 2. For example, electrically insulating ceramics or resin (plastics) is used as the material of the insulating layer constituting the wiring board 2.

  Examples of the electrically insulating ceramic used as the material of the insulating layer forming the wiring substrate 2 include an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, and a nitrided body. Examples thereof include a silicon-based sintered body and a glass ceramic sintered body.

  Examples of the resin used as the material for the insulating layer forming the wiring board 2 include epoxy resin, polyimide resin, acrylic resin, phenol resin, and fluorine resin. Examples of the fluorine-based resin include a polyester resin and a tetrafluoroethylene resin.

The insulating layer forming the wiring board 2 may be formed by laminating a plurality of insulating layers made of the above-described materials. The insulating layer forming the wiring board 2 may be formed of three insulating layers as shown in FIG. 1, or may be formed of a single layer, two layers, or four or more insulating layers. Further, as in the example shown in FIG. 1, the size of the opening of the insulating layer forming the wiring substrate 2 is varied to form a stepped portion on the upper surface, and a plurality of image sensor connection pads 3 are provided on the stepped portion. It may be.

  In addition, an external circuit connection electrode may be provided on the upper surface, side surface, or lower surface of the wiring board 2. The external circuit connection electrode is for electrically connecting the wiring board 2 and the external circuit board or the imaging device 21 and the external circuit board.

  Inside the wiring board 2, an internal wiring formed between the insulating layers and a through conductor that connects the internal wirings up and down are provided. These internal wirings or through conductors may be exposed on the surface of the wiring board 2. The external circuit connection electrode and the image sensor connection pad 3 may be electrically connected by the internal wiring or the through conductor.

  The imaging device connection pad 3, the external circuit connection electrode, the internal wiring, and the through conductor are tungsten (W), molybdenum (Mo), manganese (Mn), silver when the wiring board 2 is made of electrically insulating ceramics. (Ag) or copper (Cu) or an alloy containing at least one metal material selected from these. In addition, when the wiring board 2 is made of resin, the imaging device connection pad 3, the external circuit connection electrode, the internal wiring, and the through conductor are copper (Cu), gold (Au), aluminum (Al), nickel ( Ni), molybdenum (Mo), titanium (Ti), or an alloy containing at least one metal material selected from these.

  A plating layer may be provided on the exposed surface of the imaging element connection pad 3, the external circuit connection electrode, the internal wiring, and the through conductor. According to this configuration, the imaging element connection pad 3, the external circuit connection electrode, the internal wiring, and the exposed surface of the through conductor can be protected to suppress oxidation. Moreover, according to this structure, the image pick-up element connection pad 3 and the image pick-up element 10 can be favorably electrically connected via the connecting member 13 such as wire bonding. As the plating layer, for example, a Ni plating layer having a thickness of 0.5 to 10 μm may be deposited, or even if this Ni plating layer and a gold (Au) plating layer having a thickness of 0.5 to 3 μm are sequentially deposited. Good.

  Further, the wiring board 2 may have a lid 12 for sealing. The lid body 12 has, for example, a flat plate shape. For the lid 12, for example, when the imaging element 10 is an imaging element or a light emitting element such as an LED, a highly transparent member such as a glass material is used. The lid 12 is bonded to the upper surface of the wiring board 2 by an adhesive member 14 such as a brazing material made of a thermosetting resin, low melting point glass, or a metal component.

  The imaging element mounting substrate 1 has a bonding material 15 between the inorganic substrate 4 and the wiring substrate 2. At that time, for example, as described later, when the wiring board 2 has a notch or the like, the bonding material 15 may be exposed inside the notch in a top view.

  As a material constituting the bonding material 15, for example, a thermosetting resin or a brazing material is used. Examples of the thermosetting resin used as a material for forming the bonding material 15 include bisphenol A type liquid epoxy resin. Examples of the brazing material used as the material for forming the bonding material 15 include solder, lead, and glass.

  The bonding material 15 may have conductivity, for example. Examples of the bonding material 15 include silver epoxy, solder, anisotropic conductive resin (ACF), and anisotropic conductive film (ACP). Since the bonding material 15 has conductivity, the wiring substrate 2 and the inorganic substrate 4 can be electrically bonded. For example, by electrically bonding the wiring substrate 2 and the inorganic substrate 4 at the same potential as the ground electrode, the inorganic substrate 4 can have the role of a shield that protects the image sensor 10 from external noise.

  The part located in the peripheral region 4 a of the inorganic substrate 4 is inclined upward, and the bonding material 15 is provided inside the outer edge of the inorganic substrate 4. Even if the bonding material 15 is pressed in the bonding process or the like, it is possible to reduce the exposure of the bonding material 15 to the side surface of the inorganic substrate 4 due to the peripheral region 4a inclined upward.

  In the imaging element mounting substrate 1 according to the embodiment of the present invention described above, the portion located in the peripheral region 4 a of the inorganic substrate 4 is inclined upward, and the bonding material 15 is the outer edge of the inorganic substrate 4. It is provided inside. Accordingly, when the wiring substrate 2 and the inorganic substrate 4 are downsized, the bonding material 15 is bonded to the inorganic substrate 4 by the peripheral region 4a inclined upward even if the bonding material 15 is pressed in the bonding process or the like. It is possible to reduce the exposure to the side surface of. Therefore, it is possible to reduce the exposure of the bonding material 15 between the wiring board 2 and the inorganic substrate 4 to the outside, and to reduce the airtightness of the imaging device 21 or the bonding failure of the lens holder 19. Become.

  Further, when the bonding material 15 is made of a conductive material, the wiring substrate 2 and the inorganic substrate 4 can be electrically bonded. At this time, since the bonding material 15 is exposed to the outside, it is possible to reduce the occurrence of a short circuit due to contact with an external circuit and other components.

  Further, in the imaging element mounting substrate 1 according to the embodiment of the present invention, the portion located in the peripheral region 4 a of the inorganic substrate 4 is inclined upward, and the bonding material 15 is more than the outer edge of the inorganic substrate 4. It is provided inside. This makes it possible to relieve the stress applied from the outside of the imaging device 21 by using the peripheral region 4a as a spring. Therefore, even if the wiring substrate 2 and the inorganic substrate 4 are thinned, it is possible to reduce the possibility that the wiring substrate 2 is cracked or broken.

<Configuration of imaging module>
FIG. 2 shows an imaging module 31 using the imaging element mounting substrate 1. Imaging module 3
1 has an imaging device 21 and a lens holder 19 provided in the imaging device 21. The imaging device 21 includes an imaging element mounting substrate 1 and an imaging element 10 mounted on the central region 4b of the inorganic substrate 4 of the imaging element mounting substrate 1.

  Further, as in the example shown in FIG. 1, the outer edge of the inorganic substrate may be located inside the outer edge of the wiring substrate. As described above, since the outer edge of the inorganic substrate 4 is located at the same position or on the inner side as the outer edge of the wiring board 2, the imaging device 21 can be further downsized. Furthermore, since the outer edge of the inorganic substrate 4 is positioned inside the outer edge of the wiring substrate 2, it is possible to reduce the space between the wiring substrate 2 and the outer edge of the inorganic substrate 4. Therefore, it is possible to further reduce the exposure of the bonding material 15 to the side surface of the inorganic substrate 4.

  In addition, as in the example illustrated in FIG. 1, the upper end of the inorganic substrate 4 may be provided with a gap from the lower end of the wiring substrate 2. Thus, by providing a distance between the inorganic substrate 4 and the wiring substrate 2, it is possible to reduce the possibility that the wiring substrate 2 and the inorganic substrate 4 come into contact when the inorganic substrate 4 is stressed. It becomes possible. As a result, it is possible to reduce the transmission of stress from the inorganic substrate 4 to the wiring substrate 2, and it is possible to reduce the occurrence of cracks or cracks in the wiring substrate 2.

As in the example illustrated in FIG. 2, the imaging module 31 includes a lens holder 19. By having the lens holder 19, the airtightness is improved or the external stress is directly applied to the imaging device 2.
It is possible to reduce the addition to 1. The lens holder 19 may include, for example, a housing made of resin or metal material and one or more lenses made of resin, liquid, glass, crystal, or the like. Further, the lens holder 19 may be provided with a driving device for driving up, down, left, and right, and may be electrically connected to the wiring board 2.

  In the example shown in FIG. 2, the lower end portion of the lens holder 19 reaches the lower surface of the inorganic substrate 4 in a cross-sectional view and is provided so as to overlap with a part. As a result, the airtightness of the imaging module 31 can be further increased. Further, in this case, as in the present invention, the peripheral region 4a of the inorganic substrate 4 is inclined to the upper surface side, and the bonding material 15 is provided on the inner side of the outer edge of the inorganic substrate 4, so that the bonding material 15 is exposed to the side surface of the imaging device 21, and it is possible to reduce the deterioration of fitting property when the lens holder 19 is joined.

  Although not shown in the example shown in FIG. 2, the lens holder 19 may be provided with an opening on at least one side in the four directions when viewed from above. An external circuit may be inserted from the opening of the lens holder 19 and electrically connected to the wiring board 2. Further, the opening of the lens holder 19 may be sealed even if the external circuit is electrically connected to the wiring board 2 and the gap between the openings is closed with a sealing material such as a resin so that the inside of the imaging module 31 is hermetically sealed. Good.

  Although not shown, the inorganic substrate 4 may be provided with slits from the upper surface, the lower surface, or both the upper surface and the lower surface of the portion bent toward the upper surface side. This makes it possible to relax the stress at the bending point of the inorganic substrate 4.

<Image sensor mounting substrate and imaging device manufacturing method>
Next, an example of a method for manufacturing the imaging element mounting substrate 1 and the imaging device 21 according to the present embodiment will be described. In addition, an example of the manufacturing method shown below is a manufacturing method using many wiring boards 2 and using the wiring board.

(1) First, a ceramic green sheet constituting the wiring board 2 is formed. For example, when obtaining the wiring board 2 which is an aluminum oxide (Al ₂ O ₃ ) sintered material, silica (SiO ₂ ), magnesia (MgO) or calcia (as a sintering aid) is added to the Al ₂ O ₃ powder. A powder such as CaO) is added, an appropriate binder, a solvent and a plasticizer are added, and then the mixture is kneaded to form a slurry. Thereafter, a ceramic green sheet for taking a large number of pieces is obtained by a molding method such as a doctor blade method or a calender roll method.

  When the wiring board 2 is made of, for example, a resin, the wiring board 2 can be formed by molding by a transfer molding method or an injection molding method using a mold that can be molded into a predetermined shape. .

  Moreover, the wiring board 2 may be obtained by impregnating a base material made of glass fiber with a resin, such as glass epoxy resin. In this case, the wiring board 2 can be formed by impregnating a base material made of glass fiber with an epoxy resin precursor and thermosetting the epoxy resin precursor at a predetermined temperature.

  (2) Next, by a screen printing method or the like, the ceramic green sheet obtained in the above step (1) is coated with metal on the portions to be the imaging device connection pad 3, the external circuit connection electrode, the internal wiring, and the through conductor. Apply or fill with paste. This metal paste is prepared by adjusting an appropriate viscosity by adding an appropriate solvent and binder to the metal powder made of the above-described metal material and kneading. The metal paste may contain glass or ceramics in order to increase the bonding strength with the wiring board 2.

  (3) Next, the above-described green sheet is processed with a mold or the like. An opening is formed in the center of the green sheet that will be the wiring substrate 2. At this time, the groove 2a may be formed by a mold or the like at a predetermined position of the green sheet to be the wiring board 2.

  (4) Next, the ceramic green sheets used as the wiring board 2 are produced by laminating and pressing the ceramic green sheets used as the insulating layers. In this step, for example, a green sheet laminate to be the wiring board 2 may be produced by providing through holes in the green sheets to be the respective layers, and laminating and pressing. Further, in this step, for example, the green sheet laminated body to be the wiring board 2 may be manufactured by providing the grooves 2a in the green sheets to be the respective layers, and laminating and pressing both of them. The groove 2a may be formed after a plurality of green sheets 2 are stacked.

  (5) Next, this ceramic green sheet laminate is fired at a temperature of about 1500 to 1800 ° C. to obtain a multi-piece wiring board in which a plurality of wiring boards 2 are arranged. In this step, the above-described metal paste is fired simultaneously with the ceramic green sheet to be the wiring substrate 2, and becomes the imaging element connection pad 3, the external circuit connection electrode, the internal wiring, and the through conductor.

  (6) Next, the multi-cavity wiring board obtained by firing is divided into a plurality of wiring boards 2. In this division, a dividing groove is formed in a multi-piece wiring board along a portion serving as an outer edge of the wiring board 2, and the wiring board 2 is divided by a method of breaking and dividing along the dividing groove or a slicing method. The method etc. which cut | disconnect along the location used as the outer edge of can be used. In addition, the dividing groove can be formed by cutting less than the thickness of the multi-piece wiring board with a slicing device after firing, but the cutter blade is pressed against the ceramic green sheet laminate for the multi-piece wiring board, You may form by cutting smaller than the thickness of a ceramic green sheet laminated body with a slicing apparatus.

  (7) Next, an inorganic substrate 4 to be bonded to the lower surface of the wiring substrate 2 is prepared. When the inorganic substrate 4 is made of a metal material, the inorganic substrate 4 is produced by punching or etching using a conventionally known stamping mold on a plate made of the metal material. In addition, even when made of other materials, it can be similarly produced by punching or the like suitable for each material. Moreover, when the inorganic substrate 4 is made of a metal material such as Fe-Ni-Co alloy, 42 alloy, Cu or copper alloy, a nickel plating layer and a gold plating layer may be deposited on the surface thereof. . Thereby, the oxidative corrosion of the surface of the inorganic substrate 4 can be effectively suppressed.

  Further, when the inorganic substrate 4 is made of an electrically insulating ceramic or the like and a conductor pattern is printed on the surface, a nickel plating layer and a gold plating layer may be similarly deposited on the surface. Thereby, the oxidative corrosion of the surface of the inorganic substrate 4 can be effectively suppressed.

  At this time, it is also possible to create a portion bent to the upper surface side at a predetermined position using a press or a mold.

  (8) Next, the wiring substrate 2 and the inorganic substrate 4 are bonded through the bonding material 15. As the bonding material 15, a paste-like thermosetting resin (adhesive member) is applied to one or both bonding surfaces of the wiring substrate 2 and the inorganic substrate 4 by a screen printing method, a dispensing method, or the like. Then, after drying the thermosetting resin, the wiring substrate 2 and the inorganic substrate 4 are overlapped, and then passed through a tunnel-type atmosphere furnace or oven, and the bonding material is thermoset by pressurizing and heating. Then, the wiring substrate 2 and the inorganic substrate 4 are firmly bonded.

The bonding material 15 is made of, for example, a main agent made of bisphenol A type liquid epoxy resin, bisphenol F type liquid epoxy resin, phenol novolac type liquid resin, etc., a filler made of spherical silicon oxide or the like, or an acid anhydride such as tetrahydromethyl phthalic anhydride. It can be obtained by adding a carbon powder or the like as a curing agent mainly composed of a product or the like, and mixing or kneading with a centrifugal stirrer or the like to obtain a paste.

  In addition, as the bonding material 15, for example, bisphenol A type epoxy resin, bisphenol A modified epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, special novolac type epoxy resin, phenol Derivative epoxy resin, epoxy resin such as bisphenol skeleton type epoxy resin, etc. with addition of curing agent such as imidazole, amine, phosphorus, hydrazine, imidazole adduct, amine adduct, cationic polymerization or dicyandiamide Can be used.

  (9) Next, the image sensor 10 is mounted on the central region 4 b of the inorganic substrate 4. The image sensor 10 is electrically joined to the wiring board 2 by wire bonding or the like. At this time, an adhesive or the like may be provided on the imaging element 10 or the inorganic substrate 4 and fixed to the inorganic substrate 4. Further, the lid 12 may be joined by the adhesive member 14 after the imaging element 10 is mounted on the central region of the inorganic substrate 4.

  The imaging device 21 can be manufactured by assembling the wiring board 2 and the inorganic substrate 4 as described above. The imaging device 21 is obtained by the steps (1) to (9). In addition, the process order of said (1)-(9) is not designated.

  Further, as a method of bending the inorganic substrate 4 to the upper surface side, it can be produced by using a difference in thermal expansion coefficient between the wiring substrate 2 and the inorganic substrate 4. For example, by selecting the thermal expansion coefficient of the wiring substrate 2 to be larger than that of the inorganic substrate 4, the bonding material 15 may be caused by the difference in thermal expansion in the heating process for curing the bonding material 15. After curing, the inorganic substrate 4 can be set to bend in the direction of the upper surface side.

(Second Embodiment)
Next, an imaging element mounting substrate 1, an imaging device 21, and an imaging module 31 according to a second embodiment of the present invention will be described with reference to FIGS. The imaging device mounting substrate 1 and the imaging device 21 in the present embodiment differ from the imaging device mounting substrate 1 and the imaging device 21 in the first embodiment in that the inorganic substrate 4 is the outer side of the wiring substrate 2 in a top view. This is a more prominent point.

  In the present embodiment, the outer edge of the inorganic substrate 4 is located outside the outer edge of the wiring substrate 2. Thus, even if it is difficult to provide a clearance around the bonding material 15 due to downsizing of the wiring substrate 2, the bonding material 15 is bonded because the inorganic substrate 4 is positioned outside the outer edge of the wiring substrate 2. It is possible to further reduce exposure to the periphery of the inorganic substrate 4 due to the pressing of time.

  Further, since the outer edge of the inorganic substrate 4 is located outside the outer edge of the wiring substrate 2 in a top view, the inorganic substrate 4 can easily receive an impact such as a drop, and the wiring substrate 2 can be more impacted. It can be reduced. As a result, it is possible to reduce cracks and the like of the wiring board 2.

  FIG. 4 shows the imaging module 31 in the present embodiment. In the present embodiment, the leg portion of the lens holder 19 is located on the upper surface of the peripheral region 4 a of the inorganic substrate 4. As a result, even when the imaging module 31 is dropped or stress is applied from the upper surface of the lens holder and stress is applied to the inorganic substrate 4, the stress can be absorbed by the peripheral region 4a inclined to the upper surface side. Therefore, the deformation of the inorganic substrate 4 or the applied stress transmitted from the inorganic substrate 4 to the wiring substrate 2 and the generation of cracks or cracks in the wiring substrate 2 can be reduced.

(Third embodiment)
Next, an imaging element mounting substrate 1 and an imaging device 21 according to a third embodiment of the present invention will be described with reference to FIG. The imaging element mounting substrate 1 and the imaging device 21 in the present embodiment are different from the imaging element mounting substrate 1 and the imaging device 21 in the second embodiment in that a groove along the vertical direction is formed on the outer surface of the wiring board 2. Is a point provided.

  In the present embodiment, the wiring board 2 has a rectangular shape, and a groove 2 a extending in the vertical direction is formed on the outer surface of the wiring board 2. In general, when the groove 2a is provided on the outer surface of the wiring board 2 as in the example shown in FIG. 5, the bonding material 15 is coated by applying along the outer edge of the groove 2a with a clearance from the outer edge. Exposure to the side surface of the substrate 4 is reduced. However, due to the recent miniaturization of the wiring substrate 2, the clearance of the bonding material 15 is provided when the groove 2 a is provided in the wiring substrate 2, and the exposure of the bonding material 15 to the side surface of the inorganic substrate 4 is reduced. Tends to be very difficult. On the other hand, in the present embodiment, the peripheral region 4a of the inorganic substrate 4 is inclined to the upper surface side, so that when the bonding material 15 is applied, a clearance along the outer edge of the groove 2a is not provided. It is possible to reduce the exposure of the bonding material 15 to the side surface of the inorganic substrate 4.

  Here, the groove 2 a is provided, for example, to indicate directionality, or provided to join the lens holder 19 or other external circuit or the inorganic substrate 4. Therefore, the groove 2a may have a conductor layer on the surface, and may be electrically connected to the inside of the wiring board 2, or may be further subjected to surface treatment such as Ni plating or gold plating. Further, the leg portion of the lens holder 19 may be fitted in the groove 2a, and at that time, it may be electrically joined by a conductive joining material or the like.

  Although not shown, the imaging module 31 using the imaging device 21 of the present embodiment may be provided such that the leg portion of the lens holder is fitted in the groove 2 a and the tip thereof overlaps the bonding material 15. . As a result, even when stress is applied from the upper surface of the lens holder 19, the stress can be absorbed by the bonding material 15, so that the inorganic substrate 4 is deformed, cracked, or the inorganic substrate 4 and the wiring are connected. The possibility of peeling from the substrate 2 can be reduced. At this time, this effect can be enhanced by using a highly ductile material for the bonding material 15.

(Fourth embodiment)
Next, an imaging element mounting substrate 1 and an imaging device 21 according to a fourth embodiment of the present invention will be described with reference to FIG. The imaging element mounting substrate 1 and the imaging device 21 in the present embodiment are different from the imaging element mounting substrate 1 and the imaging device 21 in the second embodiment in that a bonding material 15 is provided on the side surface of the wiring board 2. It is a point.

  In the present embodiment, the bonding material 15 is provided over the side surface of the wiring board 2. In general, when the wiring board 2 is downsized, the bonding area between the wiring board 2 and the inorganic substrate 4 is reduced, and the bonding strength may be reduced. On the other hand, the peripheral region 4a of the inorganic substrate 4 is inclined to the upper surface, thereby reducing the exposure of the bonding material 15 to the side surface of the inorganic substrate 4 and providing the bonding material 15 over the side surface of the wiring substrate 2. As a result, the bonding material 15 forms a fillet and the bonding area can be further increased, so that the bonding strength can be improved.

  As a method of providing the bonding material 15 over the side surface of the wiring board 2 as in the present embodiment, for example, the bonding material 15 is applied to the inorganic substrate 4 so as to protrude from the outer edge of the wiring board 2, and then from the upper surface of the wiring board 2. It can be manufactured by pressurizing and pressing the bonding material 15. Alternatively, it can also be produced by increasing the surface roughness of the side surface of the wiring board 2 so that the bonding material 15 can easily climb.

(Fifth embodiment)
Next, an imaging element mounting substrate 1 and an imaging device 21 according to a fifth embodiment of the present invention will be described with reference to FIG. The imaging element mounting substrate 1 and the imaging device 21 according to the present embodiment differ from the imaging element mounting substrate 1 and the imaging device 21 according to the first embodiment in that a flexible substrate is provided between the wiring substrate 2 and the inorganic substrate 4. 5 is provided.

  In the present embodiment, a frame-like flexible substrate 5 that is provided between the upper surface of the inorganic substrate 4 and the lower surface of the wiring substrate 2 and surrounds the central region 4b is further provided. Thus, by providing the flexible substrate 5 having a low Young's modulus between the wiring substrate 2 and the inorganic substrate 4, the flexible substrate 5 can absorb the stress applied to the inorganic substrate 4. Therefore, it is possible to further reduce the stress applied to the inorganic substrate 4 from being propagated to the wiring substrate 2 and causing cracks or cracks in the wiring substrate 2.

  Further, when the bonding material 15 is made of a conductive material, the peripheral region 4a of the inorganic substrate 4 is inclined to the upper surface side, so that when the bonding material 15 spreads and is exposed to the side surface of the inorganic substrate 4, the flexible substrate 5, the bonding material 15, and other external circuit boards or electronic components may be inadvertently contacted to reduce the possibility of a short circuit or the like. In the example shown in FIG. 7, the flexible substrate 5 may be bent in the same direction as the inorganic substrate 4 in a cross-sectional view.

  The flexible substrate 5 has a base film, for example. As a material for forming the base film, an insulator made of a resin such as a polyimide film is used. Moreover, the flexible substrate 5 has a conductive layer on the upper surface of the base film. The conductive layer is made of copper, aluminum, gold, nickel, or an alloy containing at least one metal material selected from these.

  A plating layer may be provided on the exposed surface of the conductive layer. According to this configuration, the exposed surface of the conductive layer can be protected and oxidation can be suppressed. Moreover, according to this structure, the electrical connection of the electrical connection of the wiring board 2 and a conductive layer can be made favorable. As the plating layer, for example, a Ni plating layer having a thickness of 0.5 to 10 μm may be deposited, or even if this Ni plating layer and a gold (Au) plating layer having a thickness of 0.5 to 3 μm are sequentially deposited. Good. Furthermore, Sn plating may be performed on the plating layer.

  The flexible substrate 5 has a cover film provided on the upper surface of the conductive layer. The cover film is a film for protecting the surface of the conductive layer, and an adhesive is applied to one surface of a film made of a resin material such as a polyimide film, and is applied to the surface of the conductive layer other than the portion that is electrically joined to the wiring board 2. Is provided. The flexible substrate 5 and the wiring substrate 2 are connected by a conductive bonding material.

The bonding material 15 that bonds the flexible substrate 5 and the inorganic substrate 4 and the adhesive member that bonds the flexible substrate 5 and the wiring substrate 2 are made of a material that is not easily denatured by heat applied in the mounting process of the electronic element 10. Such a bonding material 15 and an adhesive member are bisphenol A type liquid epoxy resin or polyimide resin. In this case, peeling of the flexible substrate 5 and the inorganic substrate 4 or the flexible substrate 5 and the wiring substrate 2 in the mounting process of the electronic element 10 can be satisfactorily suppressed. The bonding material 15 and the adhesive member may be conductive, and the flexible substrate 5 and the wiring substrate 2 or the flexible substrate 5 and the inorganic substrate 4 may be electrically bonded. The conductive bonding material 15 or the adhesive member is, for example, silver epoxy, solder, anisotropic conductive resin (ACF), anisotropic conductive film (ACP), or the like.

  Moreover, in the example shown in FIG. 7, the flexible substrate 5 is located inside the inorganic substrate 4 in a top view. This makes it possible to unify all the references of the outer shape of the imaging device 21 at the outer edge of the inorganic substrate 4. Therefore, it is possible to further reduce the size of the imaging device 21 and to easily unify the outer dimensions of the imaging device 21.

  In addition, this invention is not limited to the example of the above-mentioned embodiment, Various modifications, such as a numerical value, are possible. For example, in the example illustrated in FIGS. 1 to 7, the shape of the image sensor connection pad 3 is a rectangular shape, but may be a circular shape or other polygonal shapes. In addition, the arrangement, number, shape, and the like of the image sensor connection pad 3 in the present embodiment are not specified. In addition, the various combinations of the characteristic part in this embodiment are not limited to the example of the above-mentioned embodiment.

DESCRIPTION OF SYMBOLS 1 ... Imaging device mounting substrate 2 ... Wiring substrate 2a ... Groove 3 ... Imaging device connecting pad 4 ... Inorganic substrate 4a ... Peripheral region 4b ... Center Area 5 ... Flexible substrate 10 ... Imaging element 12 ... Lid 13 ... Connection member 14 ... Adhesive member 15 ... Bonding material 19 ... Lens holder 21 ... Imaging device 31 ... Imaging module

Claims (9)

An inorganic substrate having a central region on which an image pickup device is mounted and a peripheral region provided so as to surround the central region;
A frame-like wiring board provided on the top surface of the inorganic substrate and surrounding the central region;
A bonding material provided between the inorganic substrate and the wiring substrate;
The image sensor mounting substrate, wherein a portion of the inorganic substrate located in the peripheral region is inclined upward, and the bonding material is provided on an inner side of an outer edge of the inorganic substrate. The imaging device mounting substrate according to claim 1,
The outer periphery of the said inorganic board | substrate is located outside the outer edge of the said wiring board, The board | substrate for image pick-up element mountings characterized by the above-mentioned. The imaging device mounting substrate according to claim 2,
The imaging element mounting substrate, wherein the bonding material is provided over a side surface of the wiring substrate. The imaging device mounting substrate according to claim 2 or 3,
The wiring board has a rectangular shape, and a groove extending in the vertical direction is formed on the outer surface of the wiring board. The imaging device mounting substrate according to claim 1,
The imaging device mounting substrate, wherein an outer edge of the inorganic substrate is located inside an outer edge of the wiring substrate. An imaging element mounting substrate according to any one of claims 1 to 5,
The imaging device mounting substrate, wherein an upper end of the inorganic substrate is provided to be spaced from a lower end of the wiring substrate. The imaging device mounting substrate according to any one of claims 1 to 6,
An image pickup device mounting substrate, further comprising a frame-like flexible substrate provided between an upper surface of the inorganic substrate and a lower surface of the wiring substrate and surrounding the central region. The imaging device mounting substrate according to any one of claims 1 to 7,
An image sensor mounted on the central region of the inorganic substrate of the image sensor mounting substrate;
An imaging apparatus comprising: a lid body provided at an upper end of the wiring board of the imaging element mounting board so as to cover a region surrounded by the wiring board. An imaging device according to claim 8,
An imaging module comprising: a lens holder provided on an outer surface of the wiring board of the imaging element mounting substrate.

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